Families on the poverty line are expected to spend up to two-fifths of their August income on back to school costs as schools make punishing demands on parents, according to a charity.

The average annual cost, including uniforms, coats, bags and stationery, is now £156 for a child at primary school and £285 for a child at secondary school, the report by Family Action found.

Items that some schools are requiring parents to buy for their children include £98 coats, £89 blazers, £38 rugby shirts and £27 jumpers.

Compulsory items, many of which can only be bought at expensive specialist shops, include jogging bottoms with the child's initials printed on them, aprons for cookery classes, and even straw boaters, the charity claims.

It said some schools expect pupils to have a summer uniform as well as a standard one, while others demand a range of branded sports wear.

It also claims parents of larger children have to pay nearly twice as much for larger size uniforms than they would for smaller sizes.

Other costs that schools expect parents to meet include textbooks, art and craft materials, school trips, and sometimes iPads.